The present application relates to a transverse electric field driving liquid crystal panel which performs rotation control of the arrangement of liquid crystal molecules in parallel to a substrate surface by a transverse electric field generated between a pixel electrode and a counter electrode. The present application also relates to an electronic apparatus having the liquid crystal panel mounted therein.
At present, liquid crystal panels have various panel structures corresponding to various driving methods including a vertical electric field display type in which an electric field is generated in the vertical direction with respect to the panel surface. For example, a transverse electric field display type panel structure is suggested in which an electric field is generated in the horizontal direction with respect to the panel surface.
In the transverse electric field display type liquid crystal panel, the rotation direction of liquid crystal molecules is parallel to the substrate surface. That is, in the transverse electric field display type liquid crystal panel, there is little rotation of the liquid crystal molecules in the vertical direction with respect to the substrate surface. For this reason, changes in the optical characteristics (contrast, luminance, and color tone) are comparatively small. That is, the transverse electric field display type liquid crystal panel has a wider viewing angle than the vertical electric field display type liquid crystal panel.
FIG. 1 shows an example of the sectional structure of a pixel region constituting a transverse electric field display type liquid crystal panel. FIG. 2 shows an example of the corresponding planar structure.
A liquid crystal panel 1 has two glass substrates 3 and 5, and a liquid crystal layer 7 filled so as to be sandwiched with the glass substrates 3 and 5. A polarizing plate 9 is disposed on the outer surface of each substrate, and an alignment film 11 is disposed on the inner surface of each substrate. Note that the alignment film 11 is used to arrange a group of liquid crystal molecules of the liquid crystal layer 7 in a predetermined direction. In general, a polyimide film is used.
On the glass substrate 5, a pixel electrode 13 and a counter electrode 15 are formed of a transparent conductive film. Of these, the pixel electrode 13 is structured such that both ends of five comb-shaped electrode branches 13A are respectively connected by connection portions 13B. At the upper end of the pixel electrode 13 in FIG. 2, a rectangular contact portion 13C is formed so as to be connected integrally to part of the electrode branches 13A and the connection portion 13B.
Meanwhile, the counter electrode 15 is formed below the electrode branches 13A (near the glass substrate 5) so as to cover the entire pixel region. This electrode structure causes a parabolic electric field between the electrode branches 13A and the counter electrode 15. In FIG. 1, this electric field is indicated by a dotted-line arrow.
The pixel region corresponds to a region surrounded by signal lines 21 and scanning lines 23 shown in FIG. 2. In each pixel region, a thin film transistor for controlling the application of a signal potential to the pixel electrode 13 is disposed. The gate electrode of the thin film transistor is connected to a scanning line 23, so the thin film transistor is turned on/off by the potential of the scanning line 23.
One main electrode of the thin film transistor is connected to a signal line 21 through an interconnect pattern (not shown), and the other main electrode of the thin film transistor is connected to a contact 25. Thus, when the thin film transistor is turned on, the signal line 21 and the pixel electrode 13 are electrically connected to each other.
As shown in FIG. 2, in this specification, a gap between the electrode branches 13A is called a slit 31. In FIG. 2, the extension direction of the slit 31 is identical to the extension direction of the signal line 21. That is, the slit 31 is formed along the Y-axis direction of FIG. 2.
For reference, FIGS. 3A and 3B show the sectional structure around the contact 25.
JP-A-10-123482 and JP-A-11-202356 are examples of the related art.